If you need 100% full capacity and you have a 30A service, you'll need a generator capable of providing 3600 Watts. A generator that size can weigh over 120 lbs though. A lot of people will opt for a lighter unit such as the Honda EU2000i which weighs 47 lbs and can have a companion which when combined with the original produces up-to 4000 watts, but isn't inexpensive. Your best bet is to figure out the consumption of the appliances that you need to use add them up and base your decision on size, weight, capacity and cost.

I bought the Honda EU3000IC as it weighs only 80 lbs give or take. It doesn't have electric start and has a smaller fuel tank compared to the much larger (but quieter) EU3000IS, but at least my wife can move it around on her own.

I use a honda eu3000is when I am camping at the race track. It is heavy, but super quiet and it sips fuel. It runs everything just fine as long as you use some common sense and remember that it is only putting out 26 amps instead of the usual 30 you'd get from shore power. I opted for it over the 'ic' unit because it was quieter amongst several other smaller details.